綠色製程香椿萃取物的抗糖尿病效果及藥理機轉探討

The Anti-diabetic Properties and Pharmacological Mechanisms of Green-processed Toona sinensis Extract

廖敏淳(Min-Chun Liao)

指導教授 ： 謝翠娟

高雄醫學大學/醫學院/醫學遺傳學研究所/碩士(2011年)

摘要

香椿的葉片長久以來被當作是營養豐富的食材與古老東方的藥材，大多數文獻報導指出香椿葉片中有生物活性的成分都是使用水或乙醇等溶劑進行萃取
，然而使用相對較低極性溶劑萃取的萃取物到目前為止尚未有人探討，在我們的研究中最主要是探討綠色製程香椿萃取物 (TS-G)是否具有抗糖尿病特性，並探討其藥理機轉。
我們用第二型糖尿病小鼠模式確認此特殊香椿萃取物的功效。小鼠之血清生化值分析是利用高雄醫學大學附設中和紀念醫院的羅氏生化儀器測量；用蘇木紫和伊紅染色法觀察肝臟組織與脂肪組織的型態；用酵素連結免疫吸附分析法定量胰島素、adiponectin和tumor necrosis factor-α (TNF-α)；運用即時定量聚合酶連鎖反應的方法去探討脂肪和肝臟組織中相關基因的表現；運用西方點墨法觀察脂肪和肝臟組織中相關蛋白質的表現。
在動物實驗中，我們觀察到綠色製程香椿萃取物可以有意義的預防血糖上升與rosiglitazone有相似的作用。當與糖尿病組做比較時，餵食綠色製程香椿萃取物的老鼠有較低的HOMA-IR數值、ALT、creatinine和adiponectin。從脂肪組織切片中，可以觀察到餵食香椿的糖尿病小鼠，有較小的脂肪細胞；而在肝臟的組織切片中，發現香椿可以有效預防脂肪肝的情形。然而綠色製程香椿萃取物並沒有增加脂肪組織中PPAR-γ的mRNA及蛋白質表現。
我們的研究發現綠色製程香椿萃取物具有預防糖尿病發生、改善胰島素敏感性和抑制脂肪肝形成，而其作用機制可能不是透過活化PPAR-γ的路徑，其真正的分子作用機轉，仍要繼續研究與觀察。從實驗當中，我們可以證明綠色製程香椿萃取物有很大潛能發展為抗糖尿病藥物或是相關的營養補充品。

關鍵字

糖尿病 ； 綠色製程

並列摘要

OBJECTIVE The leaves of Toona sinensis (TS) have been used as a nutritious food and an oriental medicine for a long time; however, the reported bioactive compounds of TS leaves are aqueous extract processed by using water or ethanol. The aims in this study are to investigate the anti-diabetic properties and pharmacological mechanisms of the green-processed TS leaf extract (TS-G).
METHODS Type 2 diabetic mice model was used in this study. The biochemical data of mice was analysed by a Roche Cobas Integra 400 Chemistry Analyzer. Hematoxylin and eosin stains were used to observe the morphological changes of adipose and hepatic tissues. Real-time polymerase chain reaction was used to measure the related gene expression. Western blotting was used to measure the related protein expression.
RESULTS Both the green-processed leaf extract of TS (TS-G) and rosiglitazone treatments significantly prevented the elevation of blood glucose in animal study. The value of homeostasis model assessment of insulin resistance (HOMA-IR) was lower in the TS-G treated mice compared to the diabetic mice. The plasma levels of ALT and creatinine were not elevated by the TS-G treatment compared to the normal mice. The cell size of adipocytes were smaller in the TS-G treated mice compared to the diabetic mice. The ballooned hepatocytes showed in the diabetic mice but not in the TS-G and rosiglitazone treated mice. TS-G could not increase peroxisome proliferator-activated receptor gamma (PPAR-γ) expression in adipose tissues.
CONCLUTIONS We provide evidence that TS-G prevented the progression of diabetes and the functional mechanisms of TS-G may not regulate through PPAR-γ pathway. Our findings suggest that the green-processed TS leaf extract may have potential in the development of anti-diabetic food supplements and medicines.

並列關鍵字

diabetes ； green-processed

參考文獻

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